How to choose refractory materials for steel rolling heating furnace

Steel rolling heating furnace is often used for heating billets or small steel ingot thermal equipment, mainly composed of furnace roof, furnace wall and furnace bottom. The long-term working temperature is lower than 1400℃. For continuous or annular heating furnaces, the furnace temperature of each part can be divided into three zones of low, medium and high temperature, and the temperature is 500-800℃ and 1150-1300℃ respectively. , 1200-1300℃.

The main reason for the damage of the furnace lining is due to temperature fluctuations caused by intermittent operation and shutdown of the furnace, resulting in deformation and peeling of the furnace lining; the main reason for the damage of the furnace bottom and the root of the furnace wall is the chemical reaction between the molten iron oxide slag and the bricks. .

According to the working conditions of the heating furnace, it is necessary to select suitable refractory materials according to the conditions of different parts to achieve a reasonable configuration of materials, so that the heating furnace lining material can have a long life and save energy. Then, how to choose refractory materials for steel rolling heating furnace:

After nearly 30 years of development, refractory materials for heating furnaces are now generally combined with refractory castables + anchoring bricks. The construction is simple, easy to operate, and low in engineering costs. It is a better material for industrial kiln construction.

01 low temperature zone

The low temperature zone is also called the preheating zone of the steel rolling furnace. Its working temperature is generally below 1200℃. The use of high alumina castable with Al2O3 content of about 50-55% can fully meet the needs of use, or light casting can be used The material used as the furnace lining can reduce the surface temperature of the furnace wall, so as to save energy and reduce consumption.

02Medium and high temperature zone

The high temperature zone is also called the heating zone and soaking zone of the steel rolling furnace. Its working temperature is generally around 1200-1350°C. A low-cement castable with an Al2O3 content of about 60% can be selected. The raw material of the castable should be selected with impurity content. Lower raw materials can improve the performance of the castable at around 1350℃.

The castable for the working lining needs to choose a masonry method combined with anchor bricks. The anchor bricks can be high-aluminum anchor bricks of national standard LZ-55.